Converts a unique identifier to a string value in the format xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx, where x is a hexadecimal digit. If the binary value is not a valid uniqueidentifier, NULL is returned.

The following statement creates a table mytab with two columns. Column pk has a unique identifier data type, and column c1
has an integer data type. It then inserts two rows with the values 1 and 2 respectively into column c1.